A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

A first calculation unit calculates an acceleration factor of lifetime consumption of the light source with as case of a standard temperature and standard drive condition as a reference, a second calculation unit calculates a whole lifetime or remaining lifetime of individual light sources relative to a performance index of the individual light sources or a change rate of the performance index, a computation unit obtains an effective cumulative driving time at which the magnitude of influence imparted on the lifetime is equivalent with a case of driving at the standard temperature and standard drive condition, by calculating a time integral of the acceleration factor, and a recording unit records the effective cumulative driving time and the whole lifetime or remaining lifetime together with an optical output characteristic of the light source.

A nitride semiconductor laser element includes a stacked structure and a dielectric multilayer film, The dielectric multilayer film includes a first dielectric film, a second dielectric film, and a third dielectric film in the stated order. The nitride semiconductor laser element satisfies the following expressions:

[00001]$.Math.\mathrm{nk}\times \mathrm{dk}+\mathrm{ni}\times \mathrm{di}+\mathrm{nj}\times \mathrm{dj}=m1\times \frac{\lambda }{4}\pm \frac{\lambda }{16};$$\mathrm{nj}\times \mathrm{dj}=m2\times \lambda /4\pm \lambda /16;\mathrm{and}$$\frac{3\lambda }{16}\leqq .Math.\mathrm{nk}\times \mathrm{dk}\leqq \frac{5\lambda }{16}.$

A photonic integrated circuit (PIC) includes a semiconductor substrate, one or more passive components, and one or more active components. The one or more passive components are fabricated on the semiconductor substrate, wherein the passive components are fabricated in a III-V type semiconductor layer. The one or more active components are fabricated on top of the one or more passive components, wherein optical signals are communicated between the one or more active components via the one or more passive components.

A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

A controller stabilizes a distributed feedback plus reflection (DFB+R) laser, which has a back facet, a DFB section, a passive section, and a front facet with a low reflective element. An etalon filter is formed by a portion of the DFB section, the passive section, and the low reflective element. Control circuitry directly modulates the DFB section with a modulation signal and biases the passive section with a bias signal. In operation, a lasing mode of the DFB section is aligned to a long wavelength edge of one of the periodic peaks of a reflection profile of the etalon filter. Meanwhile, photodiodes are arranged to monitor the output power emitted from the laser's front and back facets. The control circuitry monitors a ratio of the detected output power and adjusts the bias based on the monitored ratio.

A method of controlling an optical output power of a laser diode associated with a photodiode includes obtaining first optical trimming parameters indicative of a first optical output power of the laser diode at a first laser diode current and a second optical output power of the laser diode at a second laser diode current above lasing threshold. Next, second electrical trimming parameters indicative of a photodiode characteristic curve of photodiode current versus laser diode current are obtained. A first photodiode current and a second photodiode current at a laser diode currents below lasing threshold. A slope of a photodiode current versus laser diode current is determined. The optical output power of the laser diode above lasing threshold is controlled based on the first optical trimming parameters, the second electrical trimming parameters and the slope of the photodiode current versus laser diode current below lasing threshold.

A laser module includes: a laser diode bar including a plurality of emitters configured to emit laser light from a front surface and leak light from a rear surface; a housing including a reflecting surface configured to surround a space together with the laser diode bar and reflect, toward the space, light leaked from the rear surface, in a scattering manner; and a detector configured to detect light reflected by the reflecting surface. A laser module includes: a laser diode bar including a plurality of emitters configured to emit laser light from a front surface and leak light from a rear surface; a condenser lens on which light leaked from rear surfaces of all of the plurality of emitters impinges; and a detector configured to detect light transmitted through the condenser lens.

A laser structure may include a substrate, an active region arranged on the substrate, and a waveguide arranged on the active region. The waveguide may include a first surface and a second surface that join to form a first angle relative to the active region. A material may be deposited on the first surface and the second surface of the waveguide.

Monitoring temperature of a laser diode and adjusting usage of the laser diode based on the monitoring information. The method of monitoring includes using a laser driver circuit to drive the laser diode to deliver multiple test current stimuli at different times related to the laser driver issuing one or a burst of illumination pulses. A differential measurement can be made between at least two of the test current stimuli. The differential measurement can be used to determine an indication of the heating or health of the laser diode in the system or of the laser system as a whole.